Teaching tip Use a real world example to describe an organization with interconnected LANs.
Teaching tip An example of a regional resource is a supercomputer. For example, Pittsburgh has the Pittsburgh Super Computing center (www.psc.edu). The various colleges in Pittsburgh connect to the center through a MAN in Pittsburgh.
Teaching tip Discuss how users managing their own security settings can be bad.
Teaching tip For more information on dsl see www.dslreports.com.
Teaching tip For technical students take the time to draw the packet structure on the board. The typical structure is destination address | sending address | packet number | total packets | data size | payload | error control.
Teaching tip Have students determine IP addresses for the computer. On 2000/XP enter ipconfig /all. Windows 98 and back enter winipcfg.
Teaching tip Pages 352 and 353 have diagrams of each network topology
Insider Information The Xerox Corporation controls the assignment of Ethernet addresses to NIC manufacturers.
Insider information Twisted pair networks cannot achieve higher than 10 Mbps using a hub. Switches are necessary to achieve 100 Mbps or higher.
Discussion point Ask who in the class has high speed Internet. Then determine if anyone is sharing this to the rest of the house or dorm. If they are, see if they can describe the setup. Most likely, the sharing is done with a router.
Teaching tip Remind students that bps is bits per second. Gbps then is billion bits per second.
Simplex communication is a mode in which data only flows in one direction. Because most modern communications require a two-way interchange of data and information, this mode of transmission is not as popular as it once was.
However, one current usage of simplex communications in business involves certain point-of-sale terminals in which sales data is entered without a corresponding reply.
The fastest directional mode of communication is full-duplex communication. Here, data is transmitted in both directions simultaneously on the same channel. Thus, this type of communication can be thought of as similar to automobile traffic on a two-lane road.
Full-duplex communication is made possible by devices called multiplexers. Full-duplex communication is primarily limited to mainframe computers because of the expensive hardware required to support this directional mode.
Large network that connects different organizations
Shares regional resources
An example of a regional resource is a supercomputer. For example, Pittsburgh has the Pittsburgh Super Computing center (www.psc.edu). The various colleges in Pittsburgh connect to the center through a MAN in Pittsburgh.
Refer to applications and services that are Intranet based, and use extended, secure access to external users or enterprises. This access is usually accomplished through passwords, user IDs, and other application-level security
A value-added network (VAN) is a private network provider (sometimes called a turnkey communications line) that is hired by a company to facilitate electronic data interchange ( EDI ) or provide other network services.
Before the arrival of the World Wide Web, some companies hired value-added networks to move data from their company to other companies. With the arrival of the World Wide Web, many companies found it more cost-efficient to move their data over the Internet instead of paying the minimum monthly fees and per-character charges found in typical VAN contracts. In response, contemporary value-added network providers now focus on offering EDI translation, encryption , secure e-mail, management reporting, and other extra services for their customers.
A virtual area network (VAN) is a network on which users are enabled to share a more visual sense of community through high band-width connections.
It is something like a metropolitan area network (MAN) or extended local areanetwork ( LAN ) in which all users can meet over high-bandwidth connections, enabling "face-to-face" online "coffeehouses," remote medical diagnosis and legal consultation, and online corporate or extracorporate workgroups, focus groups, and conferences.
A VAN requires multi-megabyte data flow and can be implemented through the use of Asymmetric Digital Subscriber Line but more likely through the installation of cable modem . Since the high-bandwidth connections imply a common infrastructure, the first VANs are likely to be local or regional. However, a VAN can also be national or international in geographic scope, assuming all users share similar capabilities.
Internet Packet Exchange/Sequenced Packet Exchange
Associated with Novell Netware
Replaced by TCP/IP
IPX is a network layer protocol while SPX is a transport layer protocol . The SPX provides connection-oriented services between two nodes on the network.
IPX and SPX both provide connection services similar to TCP/IP , with the IPX protocol having similarities to IP , and SPX having similarities to TCP .
IPX/SPX was primarily designed for local area networks (LANs), and is a very efficient protocol for this purpose (typically its performance exceeds that of TCP/IP on a LAN). TCP/IP has, however, become the de facto standard protocol. This is in part due to its superior performance over wide area networks and the Internet (which uses TCP/IP exclusively), and also because TCP/IP is a more mature protocol, designed specifically with this purpose in mind.
In digital communication systems, a repeater is a device that receives a digital signal on an electromagnetic or optical transmission medium and regenerates the signal along the next leg of the medium.
Biometrics refers to methods for uniquely recognizing humans based upon one or more intrinsic physical or behavioral traits. In information technology, in particular, biometrics is used as a form of identity access management and access control. It is also used to identify individuals in groups that are under surveillance.
Biometric Devices read personal characteristics and attributes (voice ,face, retina etc) to authenticate a
An electronic signature that can be used to authenticate the identity of the sender of a message or the signer of a document, and possibly to ensure that the original content of the message or document that has been sent is unchanged.
The ability to ensure that the original signed message arrived means that the sender cannot easily repudiate it later.
A Digital Certificat e contains the digital signature of the certificate-issuing authority so that anyone can verify that the certificate is real.
A wireless protocol for exchanging data over short distances from fixed and mobile devices, creating personal area networks (PANs). It can connect several devices, overcoming problems of synchronization.
A short-range radio technology aimed at simplifying communications among Internet devices and between devices and the Internet.
A secure specification that allows users to access information instantly via handheld wireless devices such as mobile phones, pagers, two-way radios, smart phones.
Supports most wireless networks i.e.CDMA, GSM,.
WAP is supported by all operating systems.
WAPs that use displays and access the Internet run what are called micro browsers--browsers with small file sizes that can accommodate the low memory constraints of handheld devices and the low-bandwidth constraints of a wireless-handheld network.